• Faresh@lemmy.ml
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    1 year ago

    Does the OOM killer actually work for anyone? In every linux system I’ve used, if I run out of memory, the system simply freezes.

    • Fedora@lemmy.haigner.me
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      1 year ago

      Yes, it takes surprisingly long for the OOM killer to take action, but the system unfreezes. Just wait a few minutes and see whether that does the trick.

    • TauZero@mander.xyz
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      1 year ago

      It never kicks in for me when it should, but I figured out I can force trigger it manually with the magic SysRq key (Alt+SysRq+F, needs to be enabled first), which instantly recovers my system when it starts freezing from memory pressure.

      • drathvedro@lemm.ee
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        1 year ago

        Alt+SysRq+F, needs to be enabled first

        Do note that this opens up a security hole. Since this can kill any app at random and is not interceptable, if you leave your PC in a public place, someone could come up and press this combo a few times. Chances are, it’ll kill whatever the locking app you’re using.

    • Turun@feddit.de
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      1 year ago

      Yes. If you have swap the system will crawl to a halt before the process is killed though, SSDs are like a thousand times slower than RAM. Swapoff and allocate a ton of memory to see it in action.

      • sheogorath@lemmy.world
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        1 year ago

        Nvme PCIe 4 SSDs are quite fast now tho, you can get between DDR1 and DDR2 speeds from a modern SSDs. This is why Apple are using their SSDs as swap quite aggressively. I’m using a MacBook Pro with 16 GBs of RAM and my swap usage regularly goes past 20 GBs and I didn’t experience any slowdown during work.

        • Turun@feddit.de
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          1 year ago

          Depends if the allocated memory is actively used or not. Some apps do not require a large amount of random access memory, and are totally fine with a small part of random access memory and a large part of not so random access and not so often used memory.

          Alternatively I can imagine that MacOS simply has a damn good algorithm to determine what can be moved to swap and what cannot be moved to swap. They may also be using the SSD in SLC mode so that could contribute to the speedup as well.

    • Devion@feddit.nl
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      1 year ago

      Yeah, default Ubuntu LTS webserver kicked the mysqld on a stupid query (but it worked on dev - all developers, someday) not too long ago…

    • jabjoe@feddit.uk
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      1 year ago

      Oh yes. I’ve had massive compiles (well linking) which failed because of the OOM killer, and I did exactly the same, massive swap so it will just keep going. So what if it’s using disk as RAM and unusable for a few hours in the middle of the night, at least it finishes!